I used the following in a lecture called “Why you should never write your own database”. It has never been run, tested, or anything, but it serves as a good way to discuss the challenges involved in building real world databases.

Greg,
Sure. I was constrained by the fact that I had to fit both client & server code into a single PPT slide.
That doesn't leave a lot of room for playing around, you know.
And that gives you a whole new level of things to talk about regarding scaling, exactly on this issue.

On @'Justin Van Patten' comment, using OrdinalIgnoreCase speeds up the process; however, it will work correctly if you think just about English. OrdinalIgnoreCase will not work correctly on some other languages (refer to the Turkish I example on the same link you mentioned). We also have had that issue at work and we needed to update all our string compare cases to 'InvariantCultureIgnoreCase' in order to avoid such issues. Since the author of the code wanted to come with a minimal code snippet, I think his choice of 'InvariantCultureIgnoreCase' is perfect to cover other languages since not all the readers are those who code (just) English apps.

@Andre: I checked some common defintions of "database":
Wikipedia: "an organized collection of data".
Merriam-Webster online: "a usually large collection of data organized especially for rapid search and retrieval (as by a computer)".
Dictionary.com unabridged: "a comprehensive collection of related data organized for convenient access, generally in a computer".
Colins English Dictionary: "a systematized collection of data that can be accessed immediately and manipulated by a data-processing system for a specific purpose" or "any large store of information".
American Heritage (R) Science Dictionary: "A collection of data arranged for ease and speed of search and retrieval by a computer".